Ryan Zimmerman, playing through a sore right shoulder that necessitated a cortisone shot last week, has put together two straight good games, going 2-for-4 with an RBI Sunday against the Orioles and hitting an RBI double in Monday's 4-2 loss to the Rockies.
Johnson expects him to keep playing through the pain.
"I pretty much know if something's wrong, whether he tells me or not," Johnson said. "But I try not to talk about it because I want to feel like it's good."
Zimmerman was two hits shy of the 1,000-hit mark entering Tuesday's game against the Rockies.
Bryce Harper is hitting .288 in June, but is just .184 in his last 10 games. His three strikeouts Monday tied for second-most this season.
Since Sept. 12, the Nationals have a 31-17 mark on the road, the best road percentage of any team in the Majors in that span.